1. Field of the Invention
The present invention relates to a safety stop for a variable setting stator vane pivot in which the blade is equipped with top and bottom pivots, and in which the top pivot, which works within a bearing set in the engine housing, is controlled by an orientation system while the bottom pivot moves within a bearing set in an inner ring of the engine.
2. Description of the Prior Art
The adjustability of the orientation of stator in the various compressor stages is particularly desirable when one wishes to attain, for example, the greatest possible pressure while retaining a sufficient surging margin for the various stages at a given speed. As a result, the vanes of one or more compression stages have at least one pivot mounted in a bearing and capable of being operated by an operating system. If a mechanical connector, e.g., a pin joining two successive levers of the operating system, or a pin connecting one of these levers to a stationary element such as the housing, should fail to fulfill its connecting function for whatever reason (e.g., breakage or loss following disengagement of a retaining screw), there may occur either a sudden flapping of the blades, resulting in the probable surging of the entire stage, or a sustained floating of the vanes, resulting in the nearly certain breakage of one of the vanes and destruction of the succeeding rotor stages, and possibly even more serious secondary damage.
An example of variable setting stator blades is found in French Pat. No. 2,205,952 in which the preliminary compression stage and four upper compression stages are equipped with adjustable stator blades. The pivots at the top of these blades are operated by a system of rings and levers which, using a single control, changes the orientation of the vanes of each stage in question. The stator of the preliminary compression stage has blades of a relatively large size equipped with a bottom pivot capable of absorbing deflecting stress.